docs: def input_validate_str(string, name, max_len=None, exact_len=None):
      """ Input validation for strings. """
      if type(string) is not str:
          raise pyhsm.exception.YHSM_WrongInputType(name, str, type(string))
      if max_len != None and len(string) > max_len:
          raise pyhsm.exception.YHSM_InputTooLong(name, max_len, len(string))
      if exact_len != None and len(string) != exact_len:
          raise pyhsm.exception.YHSM_WrongInputSize(name, exact_len, len(string))
      return string